Wireless range calculator

The calculator computes the maximum WLAN distance at which a stable connection is achieved. The energy margin should be at least 20dB to maintain stable communication in case of a hard degradation in the conditions for the passing of radio waves. If you reduce the requirements for reliability and speed of data exchange, then the communication range increases.

The calculation is doing under the following conditions:

• • It is assumed that the receiver and transmitter antennas are in the optical line of sight. Otherwise, the line-of-sight range must be estimated.
  • The calculation does not take into account the diffraction and diffusion of radio waves by obstacles located close to the signal propagation path. To determine how much space should be free around an imaginary axis between the antennas, you can use the Fresnel zone calculator.
  • The transmitter power can be found in the equipment specifications (usually 20 dBm). If specified in mW, then use the calculator mW -> dBm.
  • Receiver sensitivity for 802.11g:
    6Mbps: -90dBm
    9Mbps: -84dBm
    11Mbps: -85dBm
    12Mbps: -82dBm
    18Mbps: -80dBm
    24Mbps: -77dBm
    36Mbps: -73dBm
    48Mbps: -72dBm
    54Mbps: -72dBm
  • The losses in the feeder depend on its length and the operating frequency. Can be calculated in the online coaxial cable loss calculator.
  • Losses in RF connectors are usually no more than 0.5 - 1dB per connector.
  • The calculation is valid for a Wi-Fi network operating in infrastructure mode, i.e., in “client to access point” mode. If the network operates in Ad-Hoc mode, when computers interact directly without using access points, then the connection speed is limited to 11 Mbps.

For stable operation, it is better to install good antennas, rather than increase the transmitter power.